Phoenix Lake – Fish Gulch trail junction loop from Mill Valley

If you're looking for a truly challenging and rewarding gravel biking experience in Marin County, the Phoenix Lake – Fish Gulch trail junction loop from Mill Valley is one of those popular routes that delivers. This difficult 28.4-mile (45.7 km) gravel biking loop packs in a substantial 3883 feet (1183 metres) of elevation gain, typically taking around 3 hours and 58 minutes to complete, making it ideal for riders with very good fitness seeking a significant day out.

What to expect on Phoenix Lake – Fish Gulch trail junction loop from Mill Valley

This loop takes you on a diverse journey through the natural beauty surrounding Mill Valley, at the base of Mount Tamalpais. You'll traverse through serene redwood forests, climb rolling hills, and descend into deep canyons, with the scenery often shifting to oak woodlands and open grasslands. From higher elevations, keep an eye out for expansive views that can include the Pacific Ocean and even the iconic Golden Gate Bridge. Be prepared for a hard gravel ride; some sections are steep and loose, and you might find yourself needing to push your bike on certain technical parts, so this route is best suited for experienced gravel bikers.

Planning your visit

This loop is a top favorite among local gravel bikers in the Mill Valley area, known for its extensive network of trails. While much of the route is gravel-friendly, it's important to note that the immediate trail around Phoenix Lake itself might not permit bikes. Always check local regulations before you go. Given the significant distance and elevation, ensure you carry plenty of water and nutrition, especially on warmer days.

Trail details

• Distance: 28.4 miles (45.7 km)
• Elevation gain: 3883 feet (1183 metres)
• Difficulty: difficult
• Estimated time: 3 hours and 58 minutes